P160 Analysis of repeat typings done on DPB, DPA, and DQA loci; the 2018 UNOS STAR files

Aim Mandatory HLA-DPB and DQA typing has recently been instituted for deceased organ donors. While these loci are not routinely used for organ allocation or listed as unacceptable antigens, if they are in the future, consistent typings will be important. We sought to determine the current state of compliance with the mandatory typing as well as to analyze repeat typings for discrepant results. Methods We examined 162,598 HLA typings submitted to UNOS on deceased donors from 10/1/87 through 12/31/17. Data was obtained with permission from UNOS as a SAS “STAR” file and analyzed with JMP® (SAS Institute). Results Prior to January, 2016, just fewer than ten percent of the 146,896 donors were typed for DPB, DPA, DQA while typing results were submitted for DPB and DQA for virtually all donors subsequently and in 76% DPA was also submitted. In the era prior to 1/1/16, less than 3% of typings were repeated. This increased to 30–36% in the current era (Table 1). The total number of discrepancies for DPB typings was 152 out of 5,495 typings that were repeated (2.8%). The most common discrepancies in DPB typing were between DPB*104:01 and 03:01 (N = 47), DPB*04:02 and 105:01(N = 29), and DPB*04:02 with 04:01 (N = 13). A number of other discrepancies were observed involving DPB*03:01, 04:02, 104:01, 105:01 and 04:01, which accounted for 71% of the DPB discrepancies. Download high-res image (223KB) Download full-size image Conclusions HLA-DPB and DQA typing of deceased donors is now mandatory. There has been excellent compliance with submission of typing results. Over three quarters of typings also include DPA results. The large proportion of repeat typings has permitted an analysis of both the rate of discrepancies and which antigens account for most of them. If these loci are to be considered for allocation, further analysis of the nature and reasons for these discrepancies will be needed to reduce the error rate.